by Raquel Villanueva, KUSA-TV, Denver

by Raquel Villanueva, KUSA-TV, Denver

They have not been set to entrap Splinter, the man-sized rat and sensei to the Teenage Muntant Ninja Turtles, but to warn kids about the health effects of smoking marijuana at an early age.

"While much still needs to be learned about the effect marijuana has on the brain, enough information is available to cause concern in terms of the negative effects marijuana can have on the developing brains of teenagers," said Dr. Larry Wolk, Colorado's public health executive director and chief medical officer.

The $2 million campaign, targeting 12- to 15-year olds, started Monday and was commissioned by the Gov. John Hickenlooper's office.

"Don't Be a Lab Rat" aims to educate teens on the adverse effects of smoking marijuana at a young age through commercials and installations at teen-friendly venues around Denver. The campaign was funded by money from legal settlements with pharmaceutical companies.

Rat cage installation will be displayed throughout Denver with campaign messaging, including one calling for volunteers for a lab experiment.

The public will have access to the studies at DontBeALabRat.com.

Voters in Colorado and Washington state legalized recreational use of marijuana in 2012.